This invention relates generally to the field of signal transmission through fiber optic cables, and more particularly to an improved connector plug of the so-called D-4 type which is permanently engaged to a terminated fiber, and selectively coupled to an adapter at one end thereof, the adapter coupling to a similar plug at another end thereof whereby the terminated fibers of each connector are placed in abutted coaxial relation for light transmission therebetween. Devices of this general type are well known in the art, and the invention lies in specific constructional details relative to incorporated means for aligning the optical centers of the fibers as closely as possible for maximum light transmission.
The known D-4 type plugs include means for adjusting the rotational relation between the terminated fiber and an alignment projection on the body of the plug for this purpose. The adjustment procedure usually includes the making of a first adjustment, the assembly of a pair of connectors to the adapter, following which a quantitative test of light transmission is made using a meter. One of the connections is then disconnected, and the above described adjustment is made in serial increments with a trial measurement for each increment until maximum light transmission is obtained.